Extraction of fusible combustibles such as montan wax



Patented Dec. 5, 1922.

MTE 'sma'rasv 1,431,715 PATENT OFFICE.

HERMANN PLAUSO IL-OF HAMBURG, GERMANY.

EXTRACTION or FUSIBLE coMBUs'rIBLns soon as mourn wax.

Ho Drawing.

To all whom it may concern:

Be it known that I, HERMANN PLAUsoN, Esthonian subject, residing atHamburg,

Germany, have invented certain new and useful Improvements in Extractionof Fusible Combustibles Such as Montan Wax, of which the following is aspecification.

Hitherto a wax which will be termed Montan wax for brevity has beenobtained by extraction from bituminous browncoal or lignite by treatingthe crude coal as it comes ,='from1 the mine, a 'fiter preliminarydrying to a water contentof 10 to with organic bitumen-solventhydrocarbons or derivatives such as pyridine, benzene, benzine or thelike with oriwithout pressure,

and the solution has been concentrated by distillation of the solvent.

This process requires the use of large quantities of benzene or otherorganic solvent with consequent great danger of fire and the process isexpensive on account of the high cost of the solvent, especially 1n viewof the 5 to 10% loss which occurs through its volatility.

Experiments to extract moist bituminous coal direct have beenunsuccessful in practice since the losses of organic solvent have beenstill greater. v

The presentinvention provides-a process on new lines in which theextraction can be performed either without organic solvents at all orusing onlyvery small quan-,

to 10% of caustic alkali, lysalbinic or: protalbinic acid or alkaliprotein compounds, etc.,.or solvents such, as benzene, benzine,pyridine, acetone, alcohol, etc., the whole of the bituminousconstituents can be emulsified. Such treatment is preferably effected ina high speed disintegrator of the type having beater arms which rotateat a peripheral velocity of 2000 metres per minute, for example thecolloid mill dGSCI'ibBdslIl my co-pending application, Serial No.437,117, filed Jan. 13th, 1921 (Case 14).

It has Application filed January 13, 1921. Serial No. 437,121.

further been demonstrated that such emul-.

sions obtained by dispersion or more correctly the bitumen articlesoccurring there inin the dispersed state, can be separated from coarsesand and coal by direct filtration. The pure dispersion containing nocoarse precipitate can then be treated with small quantities ofelectrolyte such as salts or acids and allowed to stand in suitable hightowers for the purpose of sedimentation.

. It has been-found by observation that the colloidal bitumen thencompletely deposits leaving an upper clear layer of water containing allthe water-soluble constituents,

when the water can be separated by decantation or in other known waysfrom the lower paste containing Montari wax; if large quantities of saltare present in the water they can be recovered by evaporation.

The thick bituminous mud can be worked up into Montan wax in severalways (a) v By the addition of 10 to 30% of sol-e "vent for Montan waxand heating to 110 to 130 C when two layers are formed, of which theupper layer consists of Montan wax and solvent, having a specificgravity lighter than the water containing the coal. (b) By distillationof the wet mud pref-v erably in high vacuo with superheated vapours ofhydrocarbons aloneand/or with superheated steam.

" (a) By salting out the Montan wax with concentrated salt solutions orelectrolytes of the highest possible specific gravity.

It has hitherto been proposed to extract Montan wax from coal :bytreatment an steam or by extraction. In the steam proc-fi v ess theso-called sulphur coal is' coked by superheated steam at 250 C. withfairly heavy firing. y

.According to the present invention, however, tlfese steps are employedin combi nation with the novel emulsification or dispersion stepwhich isessential for the purpose bf the invention. No coking takes place butthe separation of the bitumen from the coal depends on the noveldiscovery that it is possible to emulsify or disperse the mixture whichis a quite unexpected result. The

the disadvantage that the coal must be first dried when it is treatedwith benzine, solar oil, etc. Extraction with benzine has thedisadvantage of danger from fire and loss of solvent. According to thepresent 'procextraction process hitherto employed has Y ess, the resultis obtained by treatment direct 'with water or by using small quantitiesof tion as regards the danger of fire, there is a saving in thatpreliminary drying is unnecessary, and there is no heavy expenditureinvolved in using expensive solvents 'so that considerable advantagesare attained for the extraction of Montan wax from bituminous browncoal.

It has been proposed hitherto to distil crude brown coal bitumen heatedto 300 C.

with steam superheated to 250 C. Such a distillate was decolourized andconverted into purified Montan wax by using organic solvents.Distillation in the present process is however employed as a stepfollowing the novel emulsification or dispersion and the presentinvention further provides novel methods of distillation, e.- g., theuse of superheated vapours "of organic solvents. The distillation stepas applied according to the present invention is preferably employedwith superheated hydrocarbon vapours either alone or mixed withsuperheated steam. Vacuum can be employe In this way the distillation"temperature is lowered so that decomposition of the wax is prevented.This process yields apure Montan wax which has hitherto been impossibleby distillation processes.

Example. 20 parts of bituminous brown coal in the moist state asobtained from the mine are preliminarily ground in a mill or kollerangand then diluted with ,100 parts of water and continuously disintegratedin a high speed disintegrator which is preferably connected by a pumpwith a steam-heated agitating vessel placed over the disintegratior sothat the pump causes a continuous circulation from the disintegrator tothe heated reservoir from which the liquid, flows by gravity into thedisintegrator again. Durmg this time the mixture is heated directly orindirectly through the vapourjacket of the agitating vessel to 90 to 110C.

Dlsmtegration is continued for instance for from one half to 3 hours,depending on the type of coal and the construction of the" drsmtegrator,till a sample shows that a disperse suspension has been obtained andonly coarse parts such as sand separate out.

yThe aqueous mixture of the dispersed brown coal and the crude Montanwax emulsified ;by hot water is filtered by a suitable filter ress withcoarse filter cloth. 'The crude the cloth.

The filtered emulsion of brown coal and bitumen is allowed to standquietly in the heated state in large vessels for several hours so thatthe whole of the finely dispersed colloidal substances separate out. Byweak acidification, e. g., with 0.1 to 3% of a. strong acid, the time ofsettling can be considerably shortened and a completely clear watersolution then remains. This is drawn off and the muddy part is filteredas well as possible so that the water soluble acid salts are removed.

The residual thick mud can now be-worked up to crude Montan wax invarious ways as follows 2- (1) 10 to 30% of Montan wax solvent is addedto the mud and the mixture is heated in an autoclave to 110 to 130 C.and allowed to cool slowly. On opening, two layers are observed of whichthe upper consists of crude Montan wax and the organic solvents and thelower of wet dispersed coal of almost molecular fineness. This can beused as a colouring matter after washing and drying or can be worked upinto briquettes-for instance by adding sulphite cellulose liquor andcompressing.

There is about 15 to'20% of the finest brown coal present in the upperlayer consisting of. crude Montan wax and the solther quantities ofsolvent, the crude Montan wax is completely freed from this brown coalby filtration. Suitable solvents for the purpose are benzene and itshomologues, benzine, aniline, quinoline, alcohols, acetone and thechlorinated hydrocarbons or mixtures of these liquids.

(2) The filtered concentrated dispersed bitumen brown coal mud can betreated to separate the Montanwax from the brown coal by filtering offor othewise separating the water and distilling the solids insuperheated vapours of a solvent such as petroleum, aniline, toluene,xylene or benzene especially in vacuo. Such a distillation not onlyseparatesthe crude Montan wax from the coal, but also effects arefining. After driving ofi the distillation liquid, the product islight yellow, very pure and possesses a melting point between 85 and 87C. The distillation can also be performed by using the aniline,petroleum, or xylene Vapour with superheated steam. This effects a goodtransference of heat to the hydrocarbon used for distillation and byusing an organic solvent for the Montan wax, its separation from coaland dirt is facilitated while the distillacoal and bitumen mud withtwice to five times its amount of neutral salt solution as concentratedas possible in suitable vessels for some time (3 to 24 or more hours) to110 to 130 C. preferably under pressure. This salts out or separates outthe crude Montan wax which collects on the surface. The liquid is nowallowed to cool quietly. An uppfr layer of more or less thick crust ofcrude ontan wax is formed, a middle layer of aqueous salt solution andfine coal mud separates on the bottom. If 1 to 3% of a hydrocarbonsolvent for Montan wax is added to the salt solution the period ofsalting out can be' considerably shortened.

Instead of salting out the bitumen mud with aqueous salt solution, thesame effect can be obtained by heating with those organic substanceswhich are solvents for Montan wax when hot, for instance naphthalene orthe like.

The manufacture of emulsions of dispersed coal and crude Montan wax bymeans of water can be considerably assisted and accelerated by theaddition of dispersion accelerators such as alkali, soaps anddecomposition or intermediate products of proteins, provided that thesedo not coagulate on heating. Or gluton and its decomposition orintermediate products can be added or sugar in small quantities from 0.1to 3%; this also reduces the temperature necessary for heating.

Although the use of these substances has been proposed for themanufacture of colloidal solutions of various kinds it could not havebeen foreseen that they would be useful for transforming the brown coalintothe disperse state and simultaneously emulsifying crude Montan waxsince many substances are present in brown coal which might be expectedto oppose dispersion.

The dispersion is also accelerated if 1 to 5% of a solvent for Montanwax is added tothe emulsifying liquid before disintegration. It couldnot have been foreseen that such small quantities of solvent wouldaccelerate the dispersion of brown coal and the emulsion of the Montanwax since it is known that such hydrocarbons usually lose their solventpower by emulsification with water. 'In .some cases it has been possibleto separate out the crude Montan wax di rect if after treatment withwater so much neutral salt is added that a concentrated salt solution is.formed and then by heating -to the boiling point of the salt solution,

the Montan wax is separated out and filtered. Obviously this operationcan be performed direct with such salt solutions.

It was not known and it could not'have been foreseen that crude Montanwax or in some cases relatively pure Montan wax could be obtained frombituminous .substances b water or aqueous emulsion with hydrocar ons.Important features of the invention are the emulsification wordispersion of the raw materials by disintegration with hot water with orwithout the addition of acceleratingagents so as to obtain a finelydispersed product from which the emulsified Montan wax can be salted outby heating with concentrated salt solutions or solvents or recovered bydirect distillation with superheated hydrocarbon vapours alone or mixedwith steam and/or in vacuo.

i The same results have not been obtained by directly treating the browncoal with water without conversion into the highly dispersed state.

While the invention has been described with reference to the treatmentof bituminous coal to yield a product which has been termed Montan wax,it will be clear that the broad features of the invention are applicableto the extraction of bituminous or waxy bodies from any suitable rawmaterial such as bitumen from bituminous coal or waxy materials fromshales.

I declare that what I claim is -1. Process for extracting Montan waxfrom bituminous earthy material which in 4. Process of treatingbituminous brownv coal which includes the step of preparing an emulsionof the Montan wax contained therein with water. I

5. Process of treating bituminous brown coal which includes the step ofpreparing an emulsion of the Montan wax contained therein with water inpresence of smallquantities of an emulsifying agent.-

6. Process of treating bituminous brown coal which includes the step ofpreparing an emulsion of the Montan wax contained therein with water inpresence of small coal which includes the step of preparing an emulsionof the Montan wax contained therein with water and treating the emulsionwith a Wax solvent.

11. Process of treating bituminous brown coal which includes the step ofpreparing an emulsion of the Montan wax contained therein with water anddistilling the wax in a current of superheated solvent v'apour.

12. Process of treating bituminous brown coal which includes the step ofpreparing an emulsion of the Montan Wax contained therein with Water anddistilling the wax in a current of superheated solvent vapour andsuperheated steam.

13. Process of treating bituminous brown coal which includes the step ofpreparing

